1. Field of the Invention
This invention relates generally to the harvesting of aquaculture from bodies of water, but more specifically to methods and apparatus for the harvesting of the types of aquaculture available near the surface of the water, for example brine shrimp and brine shrimp roe, jelly fish, kelp, algae, and other creatures that live within the upper ten feet below the surface of the body of water. Although some preferred embodiments presented herein are directed to the harvesting of roe and small invertebrates, it will be appreciated that this technique can also be used for harvesting other types of plants and animals.
2. Background Art
Harvesting aquaculture from bodies of water has been a significant source of nutrition for mankind throughout history. Although advancements in watercraft have allowed vessels to become faster and larger, increases in the amount of fauna harvested generally focus on enlarging age-old methods. For example, although fishing line and nets have been used for centuries, it has been only recently that technology has allowed the use of miles-long drift nets pulled behind huge ships. Although these changes in the scope of harvesting techniques have resulted in larger yields, they have not significantly advanced the sophistication of the technology used in harvesting aquaculture.
Although larger nets can be utilized for harvesting of fish, the harvesting of smaller species which tend to live near the surface is usually accomplished through the use of small hand nets having small openings. The small size of the openings prevents escape of the aquaculture but also prevents the rapid removal of water. These harvesting techniques therefore often require the use of cranes or other machinery to enable lifting of the fine meshed nets or bags out of the water and to handle the bags once they are aboard the ship.
After the bags of the aquaculture are loaded on the ship, the ship is typically taken to shore where the aquaculture is processed and stored for land transport. The disadvantage to this method is that, in addition to the harvested aquaculture, an abundance of water, unwanted species, and detritus is also collected and hauled to shore. Large and expensive facilities must then be constructed to hold the collected materials and to separate the selected species from the unwanted materials. Due to the large amount of unwanted material collected, the separation process can be both slow and costly.
In an attempt to limit the costly land processing, attempts have been made to at least partially separate out the selected species of aquaculture on the ship. In the case of brine ship roe, this has typically been accomplished by placing the captured water and aquaculture in a settling tank. Since the roe typically has the highest buoyancy, the roe will float to the surface of the tank where it is separated from the rest of the material.
The above process, however, has several shortcomings. For example, the separation of the shrimp roe from the rest of the aquaculture is often not absolute. This is especially true where there is a large concentration of other types of aquaculture in the water or when the harvesting is being performed under rough water conditions. As a result, significant land processing is still required.
Furthermore, the process does not work where the selected species to be harvested are not the species that float on the top surface or where it is desired to collect a plurality of different species.
In addition, collection of the selected species still requires the processing of a large amount of water. This processing requires extra time and energy.